Chemical-reaction furnace.



J. L. TUFIB.

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Patented Aug. 10, 1909.

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UNITED STATES- PATENT OFFICE.

J ORN L. TUFTS, Ol BOSTON, MASSACHUSETTS, ASBIGNOR OFONE-HALF T0 MERRIMAC CHEMICAL COMPANY, A CORPORATION.

OHEIIOLL-BEAGTIGN FURNAOE.

Specicaton o! Letters Patent.

'Patented Lug'. 1.0, 1909.

Application -led June 1B, 1906, Serial No. 823,109. Renewed April 82, 1908. Serial No. 91,598.

Toallwhom'itmcycmwem:

Be it known that I, JOHN L. TUFTS, a citizen of the United States, residing at Boston, iu the county of S11-Holl: and State of Massachusetts, have invented certain new and useful Improvements in Chemical-Reaction Furnaces, of which the following is u. specication.

This invention is a furnace or reaction vessel for chemical purposes, particularly designed for carrying into effect such reactions as occur in two or more sta requiring dierent tem rature or rabb g condi tions. As examp es .of such reactions I may refer to the manufacture of hydrochloric acid by deccm sodium chlorid by means of sulfuric acid, and the manufacture of acetic acid .by the decomposition by sulfuric acid of calcium acetate.

The furnace is simple in construction4 and may be installed at moderate cost; in practice it has been found to be economical as regards of fuel and eicient as regards the reduction and recovery of the product. furnace is adapted for continuous operation; in its preferred form it comprises .independent but chambers corresponding in number to the practical working stages of the reaction, means in the chambers for stirring, or working .the charge or reaction and for transferring 1t from one chamber to another, and means for applying heat to :the cha e in the chambers in such manner as to avoi dilution of the reaction products.

The construction of the furnace is such that with an economical application of fuel the chambers may be subjected to a. temperature adapted to the character .or nage of the reaction, while avoiding overheating of the charge or of the materials of which thefurnace is composed. Preferably the chamber in which the reaction proceeds thr h its initial stage is so constructed as to raln ,the charge such stage has been completed, the charge being-,then automatically transferred to a subsequent chamber or chambers,-

systematically arranged, with suitable communicating channels, and further treated or calcined t erein at such higher temperature as may be required.

For a full understandin of my invention reference is 'made to t `e accompanying drawings, wherein:

Figure 1 is u vertical longitudinal section of a preferred form of furnace on line 1-1 of Fig. 2; Fig. 2 is a plan view ofthe apparatus shown xn Fig. 1, portions of the bevel r for operating e mechanism ng broken away; and Figs. 4 are plan views of stirring arms adap for use in the u per and lower chambers,

rring to the drawings, the ce 1s shown as compr' sx1-chambers 1, 2, communication tween which is estal lished through a vertical flue 3.

4 is a vertical shaftsuitably incased as indicated at 5, extending through the chambers and the-Hue 3 and mounted in suitable upper and lower bearings 6 and 7, the upper bearing 6 being supported by yokes -6 mounted on the furnace ea A bevel r 8 secured to the sliaft t above .the upper c amberlmesheswithabevelgearilcarried by a shaft 10 and adapted to be driven by a worm 11; for clearness of illustration the casmg of the worm gear 11, which also the bearings for the shaft 10, is removed. It will be understood that the shaft may be driven by .a bevel gear or equi-valent means secured to the lower portion thereof. The charge, which may consist in one ecific instance of sodium chlorid and sugli-ic acid in proportions, is fed, preferably continuo, to the upper c at a point near the perihery thereof. In the construction shown Y e salt is supplied to a hopper 12, and carried by a screw conveyer 13 to the chamber 1, .the acid being introduced into the casing of said conveyor intermediate its ends through pipe 14; this arrangement insures a there h mixing of the charge prior to 4its in uction into .the furnace. An aperture for the esca e of gaseous reaction products is provid at l, 1n 35 the domeof the upper reaction chamber, and communicates w1 suitable con or collecting devices as will be readily understood; and a self-sealing dischar e gate 16 is provided near the periphery o the lower chamber.

1i, 18 lrepresent. normally c losed apertures a'ording .access to the interlor of the furnace; an aperture 17' gives access to the chamber 2.

Secured `to the shaft 4 and projecting nto the upper .and lower chambers respectively are al-ms 19, 20 carrying atlpstably mountF ed plows or mixing or sti ing blades 21 work and transfer the materials, as herein after described. Said arms are shown in plan in Figs. 3, 4: The plows carnedby the arm 19 in the upper chamber are so disposed as to move the solid ortions of the mlxture inwardl and to disc arge the same by ih ie 3 into e lower chamber, the plows lnsald lower chamber being so dis as to move the miture outwrdl an to discharge it throu the ri er o enin or openings 16. 1%. will blendtcd that-Pthe sckets 22 ca rrying the plow blades are so 1n each of these arms that the materlal dlsplaced b the plows carried by one half-arm 1s moved directly into the path of a low carried by the other half-arm, thereby e ecting a positive transfer of the material in the direction above Indicated. The plows Vmay be held rigidly in the sockets o the plow arms or may have a free vertical move-ment therein.

In order to prevent the charge from massing under any conditions around end above the stirring arms, I prefer to provlde 1n each chamber one or more stationary wipers 23, 24, preferably in the form of open frames or blades of metal projecting from the domes of the respective chambers; these wipers are oscd immediately above the plow arms an serve a s above noted to p re. vent accumulation thereon df the reacting mass even when in the condition of a very stiff and heavy paste. In order to prevent accumulation of material on the sides of the chambers I preferably provide scra rs 25, illustrated as in l with the ping member of the outermost plow in each chamber.

The hearth and dome of each chamber are referably constructed of castiron, the wa of the lower chamber being indicated as interiorly faced with refractory brick. Where a comparatively high temperature is employed cast iron. may be sed to the reacting mixture and its products without serious or rapid corrosion, whereas at relatively low temperatures it is attacked with comparative rapidity owing to condensation of acid. For is reason I prefer to provide a refractory lining, as indicated at 26, for such interior surfaces as are not in immediate roximity to the llues, as, for instance, the ome o f the upper reacting chamber.

It is desirable in eiectzlng reactions of the character above described that the material should be retained in the upper chamber until the initial sta of the reaction is comlete and until 1t has reached a solid as istingilished from a asty or mobile condition. t is further esirable that the material in said up er chamber should bc subjected to a relatively low temperature, and that the rate of evolution of s therefrom should be maintained as near constant as is practicable in order that t e condensers may be eli'ectively utilized. In the hearth of the upper chamber 1 I provide one or more ripheral channels or depressions 27 into t e outer of which the fresh material 1s fed and in which it is worked by the outer plows 21, being kept by means of these vchannels or de resslons in a more or less stratified. condition. This material being in the pasty or mobile condition above described 1s not displaced from the channels by the plows, but is merely worked, stirred or moved therein until portions of it become solid, whereupon such portions are displaced from the channel by the plows, to be discharged blymliue 3 into the lower chamber. Such wor g and transfer of the material in the initial s of the reaction is automatically effect and the a ent is such as to insure the retention of le charge 1n the upper chamber until it has attained the solid state and is adapted for treatment alii a higher temperature 1n the lower chainr. In order to secure the proper temperature conditions in the res tive chambers, I refer to provide a com ustion furnace 28, liJavlng fines 29, 30, 31 extending between the chambers and thence beneath the lower chamber. Beneath the upper or initial chamher 1, and within the liuc 29,1 arrange means for preven direct access of the heated Hue gases to e hearth of said chamber: Any means which will checkr or prevent the direct circulation of the heated gases 1n contact with this hearth will suice, such, for instan as a partition exten inwardly from e settmg of the hea but providing an annular aperture around the sheathing of the vertical line 3; my preferred construction, however, is a checkergodi-froh of iIre-briclr n indicated :n.332

1g. ,providinga ea gass ace neath the hearth of the upp amber said gas space communicating t h numerous apertures 32 with the flue This arrangement of flues insures a proper distribution of heat with a marked economy of fuel. The lower or calcning chamber 2 is subjected to a high and uniform temperature, while the upper chamber receives auch mod c rate heating as the initial stage of the reaction requires, and no portion of the chambers or of the furnace construction is liable to .overheat' The meth of electing reactions herein described is claimed in my copending applicign Serial Number 322,408, filed une 19, 1

I claim:

1. A chemical reaction furnace comprising communicating chambers, means for applying heat thereto, and means for working material in said chambers and transferring it between said chumlxers, said moans oo nstructod und arranged tu retain thc material dll in one of said chambers until portions of it acquire a substantially solid condition and then to displace such solid portions to another chamber, substantially as described.

2. A chemical reaction furnace com rising communicating chambers, heating ues in proximity to said chambers, andv means for working material in said chambers and transferring it between said chambers, said means constructed and arranged to retain the material in one of said chambers until portions of it acquire a substantial] solid condition and then to displace suc solid rtions to another chamber, substantially as ascribed.

3. A chemical reaction furnace comprising super osed communicating reaction chambers, lent-ing means therefor, a rotatable vertical shaft extendil through said chambers, and plow arms an plows 1n said chambers secured to said shaft, the hearth of one of said chambers being provided with a depression or depressions adapted to retain the more fluid portions of the charge, the plows in said chamber depending into said depression, substantially as described.

4. A chemical react-ion furnace, comprisin a chamber having a hearth, a tine beneath said hearth, and an apertnred partitween said flue and tion above said flue and arranged to provide a dead gas space between said iiue and hearth, substantially as described.

5. A chemical reaction furnace comprising su communicating reaction chambcrs,va flue between said chambers, and means arranged to provide a dead gas pace betbe hearth of e upper chamber, substantially as described.

6. A chemical leaction furnace comprising su perposed substantially closed communicating reaction chambers, and means for directing heated gases between said chambers and thence beneath the lower chamber, substantially as described. Y.

'c'. A chemical reaction furnace comprising superposed communicating reaction chambers, means for directing heated gases between said chambers and thence beneath the lower chamber, and means beneath the hearth of the upper chamber for preventing free access thereto of the heated gases, substantially as described.

In testimonv whereof, I aix my signature 1n presence o two witnesses.

JOHN L. TUFTS. ivitnesses:

ARTHUR P. CARPENTER, FaANcIs M. Rrnnn. 

